Page:The parochial history of Cornwall.djvu/28

20 most unexpected. The saxa metallifera of Cornwall had always been supposed referable to a very remote period of geological epochs, far anterior to the age of organic remains; till this opinion became shaken by the discovery of shells, or of their impressions, in the hard schist rocks near Tintagell: others were subsequently found more to the south and west; till at last Mr. De la Beche has detected the remains of organized life adjacent to a productive Copper Lode.

Two other eminent geologists, whom it would be equally idle and presumptuous for me to praise, have established the fact of a formation in the northern parts of Cornwall and Devon, not less unexpected than the discovery just noticed. Professor Sedgwick and Mr. Murchison having investigated the deep-seated rocks in Wales, and in the adjacent districts, have finally traced the carboniferous series under the Severn, and so far west as the level ridge of land, extending from near Launceston to the sea coast between St. Gennys and Botreaux Castle, along which plane the escarpment manifests itself in a very conspicuous manner.

While these discoveries may be considered as in progress, a Cornish gentleman, but one whose genius does honour to the nation, Mr. Robert Weare Fox, has deduced from galvanic action on metals, on their oxides, on their sulphurets, and on their saline solutions in water, the only theory that has yet accounted for the various phenomena observed in metallic lodes; and extending still further his investigations to the recently discovered connection